Alternator

sstach

Sharpest Tool
Mar 11, 2010
419
Central IL
Willys Model
  1. Pickup
Willys Year:
  1. 1962
Hello-

I looked quickly though the discussions and didn't find it, so if it has already been discussed, sorry...

I was talked into a single wire alternator by my father in law and have recently installed it. However, I realized last night that me fuel and temp gauges on the dash are weak and don't register fully. The are new gauges and new sender units that worked fine with the old set up, but look like they are not getting enough power (?). Anyone have experience with that? Was the alternator a bad call? Should I have gone with a 3 wire? I am usually a purest, so I can already hear "you should have just left the generator in there..."

Any thoughts would be appreciated. I will do dome trouble shooting tonight.

Thanks!
 
If your gauges are working, just slow or weak. That sounds like a grounding issue. Double check all the grounds for the new alternator, also double check all the grounds under the dash for the instrument cluster.

My 2 cents to as a starting point for this issue you are having.


Welcome to the forum by the way.

Single wire alternators are a good choice for cleaner install and removing excess components that can have an internal failure.

Eric B
 
EB, you took the words right out of my mouth....of course we are all assuming it's 12 volt system :lol:
 
It is indeed 12 volt.

So there is not an obvious issue with the swap? You're not thinking: "of course it doesn't work with a single wire alt, Shane, because..."?

I wasn't sure if by removing the generator and associated external volt regulator that I have set myself up for failure. Before I spend time trouble shooting, I want to make sure I am not missing something obvious (obvious to you, that is. It is clearly not obvious to me...)

Thanks for your input, fellas. I love this forum!
 
i used a one wire alternator on mine with no problem although it is a sbc 350 all my gauges work great except gas but that is another problem. :D
 
Have you tried revving the engine up to around 1500 to 2000 RPM's to see if it will start charging? I know on 3 wire set ups, if you don't connect the voltage sensing wire correctly you have to rev them up to get the alt. to start charging.
 
I just tuned the truck the last couple of days and dropped the RPMs to about 700 (which was much lower than it was). It seems it is a little low for the alt - it sits at a low 13v at idle across the battery. When I rev it just a little (couple 100 RPMs, maybe) the voltage jumps to 14.4ish. So it is definitely charging when I am on the move. However, when I rev the engine and idle moderately high for several seconds, the gauges do not change.

I added a ground wire from the alternator case to the frame to be sure of grounding.

The gauges worked like a charm with the generator, and I have done nothing under the dash, so it is hard to believe that something has come loose there. My gen indicator light wire that had a home one the old voltage reg is now free and the horn relay has not been rewired. Not sure that that has anything to do with it - have to check the wiring diagram again and play with that (didn't think of that when I was out there).

New and interesting challenge for me. Thanks for all the ideas. I'll keep trying and then check in with more...

Thanks - -
 
Eric B said:
If your gauges are working, just slow or weak. That sounds like a grounding issue. Double check all the grounds for the new alternator, also double check all the grounds under the dash for the instrument cluster.

My 2 cents to as a starting point for this issue you are having.


Welcome to the forum by the way.

Single wire alternators are a good choice for cleaner install and removing excess components that can have an internal failure.

Eric B
No disrespect here eric, but if a vehicle is wired properly the ground wire from the battery bolts to the block and the positive cable goes to the starter or remote solenoid then heavy cable to the starter. The reason for this the starter draws so many amps and the solenoid is really just a monster relay to handle the amperage. with ALL THAT BEING SAID WITH THE BLOCK BEING BOLTED TO THE GROUND CABLE THE BLOCK AND EVERY THING BOLTED TO IT IS AUTOMATICALLY GROUNDED. where WE COME INTO GROUNDING PROBLEMS IS WHERE GROUNDING STRAPS HAVE BEEN REMOVED FROM THE BLOCK TO THE FRAME AND FROM THE BLOCK TO THE BODY, before THIS POST i WASN'T AWARE OF A ONE WIRE ALTERNATOR SO i DID A SEARCH FOUND SOME INTERESTING LITERATURE ABOUT IT AND i AM POSTING IT, NOW BACK TO THE PRESENT PROBLEM IF THEY WORKED BETTER WITH THE GENERATOR I WOULD SUGGEST TAKING A SEROUS LOOK AT THE MODIFICATION OF THE WIRING DONE ON THE SWAP MAKE SURE YOU HAVE AT LEAST A 10 GAUGE WIRE RUNNING FROM THE ALTERNATOR TO THE SOLENOID WHERE THE POSITIVE CABLE GOES OR IF YOU HAVE A POSITIVE CABLE WITH AN ACCESSORY WIRE COMING OUT OF THE TERMINAL HOOK IT AT UP TO IT DO NOT HOOK IT UP TO THE BOLT TIGHTENING THE TERMINAL. NEW HEAVY DUTY CABLES WOULD BE A GOOD IDEA OR MAKE SURE PRESENT CABLES ARE GOOD NOT CORRODED, CLEAN AND TIGHT. MAKE SURE ALL CONNECTIONS EVERY WARE ARE TIGHT BATTERY,SOLENOID/STARTER, ALTERNATOR. (SORRY ABOUT ALL THE CAPS I TYPED ABOUT HALF WAY BEFORE I REALIZED I HIT CAP BUTTON AND DID NOT WANT TO FIX) JORP
http://www.alternatorparts.com/what_is_ ... rnator.htm
 
Bob,
No issue. I agree with you on how the original grounds are set up. Personally when I am doing any kind of vehicle re-wire, I will make sure there is overkill on grounds. With my wagon going back together, I will actually have to grounding straps from the engine to the frame and one from the frame to the body. This will help with making sure as my wiring harness goes in that I have a constant solid ground all the way around. I do agree with you on possiblilty of internally corroded battery or ground wires that my be hidden giving a poor or weak connection. If the cables are too small in gauge it can effect the flow of voltage.

Good Luck Shane.

Let us know what your outcome is.

Thanks.
Eric B
 
Thanks guys. I am using 10 gauge currently, but maybe will try more and see what happens. I hope to work on it tonight, but the wife signed us up for a 2 hour baby class tonight, so not sure I'll have time. I've got a baby boy coming July 4th (I hope). Maybe we'll call him "Willy...".

She'll never go for that...

Thanks, guys. I'll let you know what happens...
 
I hate electricity in ANY form....6 or 12 volt and house wiring. I'm not excited about changing a light bulb. I don't want to know either.... I stay away from it because it will bite. Wiring can confuse me...EZ Wiring has a wiring harness that has all wires marketed what they represent with good instructions. But that's only good if you are replacing the entire system. Searching for shorts, exposed wire, bad grounds, corrosive connections....drives me crazy.....my mind is like a TV Test Screen of the late 50's.
sstach....just for you to tackle this head ache is amazing....Congrats on your up coming birth of a child...that is special...I pray all goes well with the birth!
 
Shane,
Congrats on the new member of the family that will be arriving soon. Keep momma happy so she can keep cooking him for ya.... :thumbupleft: That's one thing I learned with my 2 munchkins.

Any luck on getting a second look at the charging system with new info???

Eric
 
Oh, the agony... This is starting to hurt my brain! I'm glad for the sympathy.

Here is what I know now: I tested the fuel gauge. It is getting full battery voltage. I light tested the temp gauge. It blinks as it is supposed to. Coil resistance is within normal limits.

Today I will mess with grounds a little more. My current main ground goes from Bat to coil bracket. I read somewhere that I should move that to the starter body, so I might do that. I have straps from the block to the frame, but I might run a wire to do that, just to be safe. When I checked the voltage to the gauge, I grounded to the dash. I will try to ground the gauges separately to see if I have lost some ground between the speedo and the dash.

Any other suggestions? I am getting desperate. Luckily I have a leaky front oil seal on my TC that will be a welcome distraction if needed.

Thanks for the well wishes with the kid and your advice. I'll do the best I can to keep the wife happy. When the wife is happy...
 
Shane, the ground wire doesn't need to be bolted to the starter body any where on the block is o k if it starts the ground from the battery to the block isn't the problem. You said you have ground straps from the block to the frame, what about from the block to the body or frame to the body? Try disconnecting the power wire to one of the gauges and run a temporary wire from the output of the alternator ( will be the same as hooking up to the battery) to the gauge start it and see if it works that way if it does then the problem is in your wiring.
 
As mentioned in another post, the fuel gauge is back on line. In all of my fussing, something has changed for the better. The problem is I am not sure what, so that is not so comforting. But now that it is working, I can't get it to stop in order to find the problem. I have tested only with the ignition on, not with the truck running (didn't have the time today), so tomorrow I will see how that goes, and check in on the temp gauge.

Bob - I may still take you up on your offer. If you are willing, I'd like to run by you what I have and you can tell/warn me of any potential fire hazards I have created!

Hey - what is with voltage, anyway? These are 12v gauges, right? But when the alt is turning, the voltage at the battery is 14.4v. That doesn't mess with the gauges? Is it because the sender drops the voltage along the way, and so it doesn't matter what the voltage of the system is?

ANYWAY - Thanks again for all of your thoughts and suggestions. Better to be lucky than good, sometimes, I guess. Let's just hope the gremlins are gone for good...
 
Your 12 volt rated gauges will work fine with 14.4 volts, the engineers who built them knew the alternator would raise the voltage, but they knew if they rated them at 14 or 15 volts people would think they could not put them in a 12 volt car. If you could check the voltage when the motor is cranking you would probably show about 10 volts and the gauges handle it just fine too.
 
Here's some info for you. A one-wire alt. typically is just connected to the battery and is constanly charging. The battery is the sole distributor for your vehicle electrics, so if it's not in the best of shape, nothing else will be while in operation. While it's a little more challenging to install a three-wire hookup alternator, your electrical system will like it better. You can go to www.madelectrical.com and get some good info on this stuff.

Lee
 
Thanks. I have since read more and more about how my 1 wire purchase may have been a little hasty. If it goes, I might look into a 3. Ease of set up is not that big a priority, really. Now, my 1 wire has a black cap over the other two "poles," and I read that in some cases you can pull that cap off and wire it as a 3 wire. I'm not sure how I would know that for sure, and so I won't mess with it.

Thanks again!
 
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